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Behavioral Pattern
In software engineering, behavioral design patterns are design patterns that identify common communication patterns among objects. By doing so, these patterns increase flexibility in carrying out communication. Design patterns Examples of this type of design pattern include: ; Blackboard design pattern : Provides a computational framework for the design and implementation of systems that integrate large and diverse specialized modules, and implement complex, non-deterministic control strategies ; Chain-of-responsibility pattern : Command objects are handled or passed on to other objects by logic-containing processing objects ;Command pattern : Command objects encapsulate an action and its parameters ;"Externalize the stack" : Turn a recursive function into an iterative function that uses a stack ; Interpreter pattern : Implement a specialized computer language to rapidly solve a specific set of problems ; Iterator pattern : Iterators are used to access the elements of an aggreg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visitor Pattern
A visitor pattern is a software design pattern that separates the algorithm from the object structure. Because of this separation, new operations can be added to existing object structures without modifying the structures. It is one way to follow the open/closed principle in object-oriented programming and software engineering. In essence, the visitor allows adding new virtual functions to a family of classes, without modifying the classes. Instead, a visitor class is created that implements all of the appropriate specializations of the virtual function. The visitor takes the instance reference as input, and implements the goal through double dispatch. Programming languages with sum types and pattern matching obviate many of the benefits of the visitor pattern, as the visitor class is able to both easily branch on the type of the object and generate a compiler error if a new object type is defined which the visitor does not yet handle. Overview The Visitor design pattern i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Engineering
Software engineering is a branch of both computer science and engineering focused on designing, developing, testing, and maintaining Application software, software applications. It involves applying engineering design process, engineering principles and computer programming expertise to develop software systems that meet user needs. The terms ''programmer'' and ''coder'' overlap ''software engineer'', but they imply only the construction aspect of a typical software engineer workload. A software engineer applies a software development process, which involves defining, Implementation, implementing, Software testing, testing, Project management, managing, and Software maintenance, maintaining software systems, as well as developing the software development process itself. History Beginning in the 1960s, software engineering was recognized as a separate field of engineering. The development of software engineering was seen as a struggle. Problems included software that was over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scheduled-task Pattern
A scheduled-task pattern is a type of software design pattern used with real-time systems. It is not to be confused with the "scheduler pattern". While the scheduler pattern delays access to a resource (be it a function, variable, or otherwise) only as long as absolutely needed, the scheduled-task pattern delays execution until a determined time. This is important in real-time systems for a variety of reasons. References External links * * See also *Command pattern *Memento pattern The memento pattern is a software design pattern that exposes the private internal state of an object. One example of how this can be used is to restore an object to its previous state (undo via rollback), another is versioning, another is custom s ... Software design patterns {{compu-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Creational Pattern
In software engineering, creational design patterns are design patterns that deal with object creation Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an a ... mechanisms, trying to create objects in a manner suitable to the situation. The basic form of object creation could result in design problems or in added complexity to the design due to inflexibility in the creation procedures. Creational design patterns solve this problem by somehow controlling this object creation. Overview Creational design patterns are composed of two dominant ideas. One is encapsulating knowledge about which concrete classes the system uses. Another is hiding how instances of these concrete classes are created and combined. Creational design patterns are further categorized into object-creational patterns ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concurrency Pattern
In software engineering, concurrency patterns are those types of design patterns that deal with the multi-threaded programming paradigm. Examples of this class of patterns include: * Active object * Balking pattern * Barrier * Double-checked locking * Guarded suspension * Leaders/followers pattern * Monitor object * Nuclear reaction * Reactor pattern * Readers–writer lock * Scheduler pattern * Thread pool pattern * Thread-local storage See also * '' Design Patterns'' (book) * Behavioral pattern * Creational pattern In software engineering, creational design patterns are design patterns that deal with object creation Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not ex ... * Structural pattern References External links ScaleConf Presentation about concurrency patternsGopherCon Rethinking Classical Concurrency Patterns [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inheritance (object-oriented Programming)
In object-oriented programming, inheritance is the mechanism of basing an Object (computer science), object or Class (computer programming), class upon another object (Prototype-based programming, prototype-based inheritance) or class (Class-based programming, class-based inheritance), retaining similar implementation. Also defined as deriving new classes (#Subclasses and superclasses, sub classes) from existing ones such as super class or Fragile base class, base class and then forming them into a hierarchy of classes. In most class-based object-oriented languages like C++, an object created through inheritance, a "child object", acquires all the properties and behaviors of the "parent object", with the exception of: Constructor (object-oriented programming), constructors, destructors, operator overloading, overloaded operators and friend functions of the base class. Inheritance allows programmers to create classes that are built upon existing classes, to specify a new implementat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Program Skeleton
Skeleton programming is a style of computer programming based on simple high-level program structures and so called dummy code. Program skeletons resemble pseudocode, but allow parsing, compilation and testing of the code. Dummy code is inserted in a program skeleton to simulate processing and avoid compilation error messages. It may involve empty function declarations, or functions that return a correct result only for a simple test case where the expected response of the code is known. Skeleton programming facilitates a top-down design approach, where a partially functional system with complete high-level structures is designed and coded, and this system is then progressively expanded to fulfill the requirements of the project. Program skeletons are also sometimes used for high-level descriptions of algorithms. A program skeleton may also be utilized as a template that reflects syntax and structures commonly used in a wide class of problems. Skeleton programs are utilized i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Template Method Pattern
In object-oriented programming, the template method is one of the behavioral pattern, behavioral Software design pattern, design patterns identified by Gamma et al. in the book ''Design Patterns''. The template method is a method in a superclass, usually an abstract superclass, and defines the skeleton of an operation in terms of a number of high-level steps. These steps are themselves implemented by additional ''helper methods'' in the same class as the ''template method''. The ''helper methods'' may be either ''abstract methods'', in which case subclasses are required to provide concrete implementations, or ''Hooking, hook methods,'' which have empty bodies in the superclass. Subclass (computer science), Subclasses can (but are not required to) customize the operation by Method overriding, overriding the hook methods. The intent of the template method is to define the overall structure of the operation, while allowing subclasses to refine, or redefine, certain steps. Overvi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strategy Pattern
In computer programming, the strategy pattern (also known as the policy pattern) is a behavioral software design pattern that enables selecting an algorithm at runtime. Instead of implementing a single algorithm directly, code receives runtime instructions as to which in a family of algorithms to use. Strategy lets the algorithm vary independently from clients that use it. Strategy is one of the patterns included in the influential book '' Design Patterns'' by Gamma et al. that popularized the concept of using design patterns to describe how to design flexible and reusable object-oriented software. Deferring the decision about which algorithm to use until runtime allows the calling code to be more flexible and reusable. For instance, a class that performs validation on incoming data may use the strategy pattern to select a validation algorithm depending on the type of data, the source of the data, user choice, or other discriminating factors. These factors are not known until runt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
State Pattern
The state pattern is a Behavioral pattern, behavioral software design pattern that allows an object to alter its behavior when its internal state changes. This pattern is close to the concept of finite-state machines. The state pattern can be interpreted as a strategy pattern, which is able to switch a strategy through invocations of methods defined in the pattern's interface. The state pattern is used in computer programming to encapsulate varying behavior for the same object (computer science), object, based on its internal state. This can be a cleaner way for an object to change its behavior at runtime without resorting to conditional statements and thus improve maintainability. Overview The state design pattern is one of twenty-three Design Patterns, design patterns documented by the Gang of Four that describe how to solve recurring design problems. Such problems cover the design of flexible and reusable object-oriented software, such as objects that are easy to implement, cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Algebra
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denoted by 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses logical operators such as Logical conjunction, conjunction (''and'') denoted as , disjunction (''or'') denoted as , and negation (''not'') denoted as . Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction, and division. Boolean algebra is therefore a formal way of describing logical operations in the same way that elementary algebra describes numerical operations. Boolean algebra was introduced by George Boole in his first book ''The Mathematical Analysis of Logic'' (1847), and set forth more fully in his ''An Investigation of the Laws of Thought'' (1854). According to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Logic
In computer software, business logic or domain logic is the part of the program that encodes the real-world business rules that determine how data can be created, stored, and changed. It is contrasted with the remainder of the software that might be concerned with lower-level details of managing a database or displaying the user interface, system infrastructure, or generally connecting various parts of the program. Details and example Business logic: * Prescribes how business objects interact with one another * Enforces the routes and the methods by which business objects are accessed and updated Business rules: * Model real-life business objects (such as accounts, loans, itineraries, and inventories) Business logic comprises: * Workflows that are the ordered tasks of passing documents or data from one participant (a person or a software system) to another. Business logic should be distinguished from business rules. Business logic is the portion of an enterprise system which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
